Abstract
Both uptake and loss of GA1 consist of two distinct transport components. The distribution of GA1 within oat coleoptile cells may thus be in at least two pools, which might arise from compartmentation, localization, or binding of GA1. There is a net uptake of GA1, supplied at physiological levels (1.16 × 10−7 M), into the slowly exchanging pool and an immobile metabolite of GA1 (probably GA8) is produced. This is treated as a third pool within the cells.